Abnormal neutrophil chemotaxis and random migration induced by aminoglycoside antibiotics

Gentamicin and amikacin, administered in therapeutic doses to normal healthy adults, caused a transient decrease in chemotactic migration of their polymorphonuclear leukocytes (PMNs). In contrast, random migration leukocytes obtained from these individuals was increased significantly. The magnitude of these changes did not correlate with the serum antibiotic concentrations. Separate in vitro experiments with gentamicin, however, revealed an inverse dose-response relationship with chemotactic suppression. The mechanism(s) involved in modifications of these leukocyte functions is not well understood. These findings may be of clinical significance in patients, especially those with altered host defense mechanisms, who require therapy with these aminoglycoside antimicrobial agents.